Researchers have discovered that Florida carpenter ants can perform amputations and clean wounds to prevent infection from spreading.
Florida ants can perform life-saving surgeries on their injured peers, according to a study published on July 2 in the journal Current Biology. They are the second species in the world capable of this, after humans. Researchers found that Florida carpenter ants (Camponotus floridanus) recognize wounds on their injured nest mates and then treat them by cleaning or amputating.
Florida carpenter ants amputating legs of injured peers. (Photo: Bart Zijlstra).
“Regarding amputation behavior, this is the only case where an individual performs a complex and systematic amputation process for another member of the same species in the animal kingdom,” concluded Erik Frank, the lead author of the study and a behavioral ecologist at the University of Würzburg, Germany.
In 2023, Frank’s research team discovered that an African ant species, Megaponera analis, can treat infected wounds in colony members using antibacterial compounds secreted from their glands. Florida carpenter ants lack similar glands, so the research team wanted to understand how these ants manage their peers’ wounds.
Specifically, the researchers examined two types of leg wounds: lacerations on the thigh and at the joint. In their experiment, they observed carpenter ants treating thigh wounds by cleaning them with their mouths and then performing amputations by biting multiple times. Meanwhile, they only cleaned the wounds at the joint. The surgical procedure significantly improved the survival rates of the injured ants. The survival rate for thigh wounds increased from under 40% to 90-95% after amputation, while the survival rate for joint wounds rose from 15% to 75% after cleaning.
Scientists believe that ants only amputate for thigh wounds rather than all leg wounds due to speed limitations. The ants take at least 40 minutes to complete an amputation. After examining the CT scans of carpenter ants, Frank and his colleagues speculated that damage to the blood-pumping muscles in the thigh slows down circulation. This delay allows bacteria-filled blood more time to spread throughout the body, giving the ants sufficient time to perform the amputation.
In contrast, the joint of the ant has relatively little muscle tissue, making the infection spread more quickly. This means that carpenter ants take too long to amputate to prevent harmful bacteria from spreading, so they focus on cleaning the wound. “Ants can diagnose wounds, assess whether they are infected or sterile, and treat them according to the condition over time. This is the only healthcare system that can be compared to humans,” Frank stated.
The ability of ants to recognize and treat wounds is innate, and researchers found no evidence of learned behavior. They are currently expanding their research to other ant species that do not possess special antibacterial glands to see if they can perform surgeries as well.
